Technical Abstract:
Wind erosion affects air quality in the Columbia Plateau of eastern Washington, north central Oregon, and western Idaho. Indeed, several locations in eastern Washington have failed to meet the PM10 air quality standard due to elevated dust emissions from agricultural fields during high wind events. Soil management practices are therefore sought that will reduce dust emissions and improve air quality in the region. Research conducted in eastern Washington has demonstrated that PM10 emissions can be reduced by increasing roughness and crop residue cover on the soil surface. In addition, conservation tillage can reduce soil loss by 75 % as compared with conventional tillage practices. The Pacific Northwest PM10 regional transport model, developed in collaboration with Washington State University, provides greater capability for assessing the impact of soil management on air quality across the Columbia Plateau. These simulations suggest that maintaining 25% residue cover on agricultural fields would reduce dust emissions and thereby PM10 concentrations below the current air quality standard across the Plateau. However, few management options are yet available to producers that are as economically viable as the conventional winter wheat ' fallow system which creates a bare and smooth surface as a result of multiple tillage operations during the fallow cycle.